#include <iostream>
#include <cstdio>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
using namespace std;

int main()
{
    umask(0);
    open("./open.txt",O_WRONLY | O_CREAT | O_WRONLY,0666);
    return 0;
}
